There is considerable interest in apparatus operable with film units adapted for so-called instant photography wherein each film unit is constructed integrally with a packet of film-developing chemicals. Such apparatus are disclosed in Douglas, U.S. Pat. No. 4,800,400; Norris, U.S. Pat. No. 4,847,632; Norris, U.S. Pat. No. 4,804,982; and Norris, U.S. Pat. No. 4,985,714. In such film processing apparatus, an optical system illuminates a photosensitive film so as to develop images on the film. Each film unit is then advanced to a printing station which has pressure driving rollers which grasp a leading edge of the film unit and dispose onto the film unit developing chemicals from a chemical holding packet of the film unit. While specific configurations of the film processing apparatus may vary, one class of apparatus that is of considerable importance employs a film slot positioned along a path of film conveyance at a location following the pressure driving rollers. This location of the exit slot presents a manufacturing convenience in that rotation of the rollers serves to deliver a processed film unit via the exit slot to persons who wish to receive the processed film units.
From the User's standpoint, it is highly desirable that such apparatus present successive film units in a manner allowing the User to either temporarily store or to withdraw selected dispensed film units. Moreover, it is desirable that an arrangement for providing these operations occupy a minimum of space, be of simple construction, be effective, and be low in cost.
A number of system approaches for film delivery have been provided with photographic cameras of the instant-development type. Examples of such systems are disclosed in U.S. Pat. Nos. 2,467,320; 3,653,308; and 3,748,990.
Of particular interest and convenience is a film printer apparatus with an articulated catcher assembly disclosed in the aforementioned U.S. Pat. No. 4,985,714 by Norris. Therein, a dispenser is operative with a film exit slot and film ejection rollers of a film processing apparatus. The dispenser has a general configuration of a four-bar mechanical linkage wherein one bar of the linkage is formed by a sidewall of a housing enclosing the film processing apparatus. An exit slot is provided in the sidewall for discharge of the film units from the housing. Some form of ejection device, such as rotating pressure driving rollers, is provided to forcibly deliver film units via the slot outward from the housing The dispenser includes a catcher formed by a tray pivotally supported by a strut assembly, both of which swing outward from the sidewall. The tray is connected in articulating fashion by a flap to the sidewall The tray, the strut assembly, and the flap constitute, respectively, a second bar, a third bar, and a fourth bar of the foregoing four-bar linkage. Upon an outward swinging of the strut assembly, the tray and the flap extend forward of the sidewall in a substantially coplanar relationship for support of the film units. Upon swinging of the strut assembly back towards the sidewall, the tray and flap fold against each other, in orientations essentially parallel to the sidewall, in a compact retracted state of the catcher. The tray is sufficiently long to extend along the sidewall beyond the slot so as to serve as a door for closing the slot in the retracted state of the catcher. Also included in the dispenser is a prestressed spring which continually urges the catcher from the extended state to the retracted state.
Automatic operation of the catcher is obtained by directing exiting film units towards the tray for urging the tray away from the sidewall The film units have sufficient beam strength, namely, resistance to bending, to overcome the retractive force of the prestressed spring Thus, upon ejection of a film unit against the tray, the strut assembly swings outward away from the sidewall allowing the tray and the flap to assume the extended substantially coplanar orientation for support of the film unit. In order to retain the catcher in the extended state against the retractive force of the spring, even after a film unit has been fully ejected from the slot to be totally supported by the catcher, a rigid hook assembly integrally formed with the tray slidably grips the side edges of the film unit as the film unit exits the slot to lie upon the tray. In this way, the first ejected film unit is held against a coplanar surface of the tray. As noted above, the beam strength of the film unit is sufficient to overcome the retracted force of the prestressed spring so as to prevent the folding of the flap against the tray. Thus, the catcher is immobilized by the presence of the first ejected film unit. Subsequent film units can readily stack upon the first film unit and the catcher which thereby stores the film units in a position which allows a person to examine selected ones of the film units. Upon removal of all of the film units from the catcher, the flap is then free to fold against the tray in response to the prestressed spring. Thus, the prestressed spring urges articulation of the catcher to the retracted state.
The foregoing Norris catcher assembly is convenient to use because the four-bar linkage can be activated by pressure of the leading edge of an ejected film unit to spring from the retracted state to the extended state. Excessive film units then stack up upon the extended tray and retraction of the catcher is brought about by the removal of the film units from the catcher. Thus, the catcher assembly is fully automated.
However, the Norris catcher assembly suffers from the disadvantage in that it is sometimes prone to image-destroying jams. After the first film unit slides under the rigid hooks so as to keep the catcher in the extended state, subsequently emerging film units can also slip underneath the rigid hooks until all the clearance between the rigid hooks and the catcher is occupied and a jam occurs.